Hi Carlo
On 20/01/2023 11:35, Carlo Marcelo Arenas Belón wrote:
Commands `git switch -C` and `git checkout -B` neglect to check whether
the provided branch is already checked out in some other worktree, as
shown by the following:
$ git worktree list
.../foo beefb00f [main]
$ git worktree add ../other
Preparing worktree (new branch 'other')
HEAD is now at beefb00f first
$ cd ../other
$ git switch -C main
Switched to and reset branch 'main'
$ git worktree list
.../foo beefb00f [main]
.../other beefb00f [main]
Fix this problem by teaching `git switch -C` and `git checkout -B` to
check whether the branch in question is already checked out elsewhere.
Unlike what it is done for `git switch` and `git checkout`, that have
an historical exception to ignore other worktrees if the branch to
check is the current one (as required when called as part of other
tools), the logic implemented is more strict and will require the user
to invoke the command with `--ignore-other-worktrees` to explicitly
indicate they want the risky behaviour.
This matches the current behaviour of `git branch -f` and is safer; for
more details see the tests in t2400.
As I said before, it would be much easier for everyone else to
understand the changes if you wrote out what they were rather than
saying "look at the tests". I do appreciate the improved test
descriptions though - thanks for that.
Reported-by: Jinwook Jeong <vustthat@xxxxxxxxx>
Helped-by: Eric Sunshine <sunshine@xxxxxxxxxxxxxx>
Helped-by: Rubén Justo <rjusto@xxxxxxxxx>
Helped-by: Phillip Wood <phillip.wood123@xxxxxxxxx>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@xxxxxxxxx>
---
Changes since v3
* Code and Tests improvements as suggested by Phillip
* Disable unreliable test that triggers a known bug
Changes since v2
* A leak free implementation
* More details in commit as suggested by Junio
Changes since v1
* A much better commit message
* Changes to the tests as suggested by Eric
* Changes to the logic as suggested by Rubén
builtin/checkout.c | 32 ++++++++++++++++++++++++--------
t/t2400-worktree-add.sh | 34 +++++++++++++++++++++++++++-------
2 files changed, 51 insertions(+), 15 deletions(-)
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 3fa29a08ee..0688652f99 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1474,7 +1474,8 @@ static void die_if_some_operation_in_progress(void)
}
static int checkout_branch(struct checkout_opts *opts,
- struct branch_info *new_branch_info)
+ struct branch_info *new_branch_info,
+ char *check_branch_path)
{
if (opts->pathspec.nr)
die(_("paths cannot be used with switching branches"));
@@ -1533,13 +1534,13 @@ static int checkout_branch(struct checkout_opts *opts,
if (!opts->can_switch_when_in_progress)
die_if_some_operation_in_progress();
- if (new_branch_info->path && !opts->force_detach && !opts->new_branch &&
- !opts->ignore_other_worktrees) {
+ if (!opts->ignore_other_worktrees && !opts->force_detach &&
+ check_branch_path && ref_exists(check_branch_path)) {
I think check_branch_path is NULL if opts->ignore_other_worktrees is set
so we could maybe lose "!opts->ignore_other_worktrees" here (or possibly
below where you set check_branch_path).
int flag;
char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
- if (head_ref &&
- (!(flag & REF_ISSYMREF) || strcmp(head_ref, new_branch_info->path)))
- die_if_checked_out(new_branch_info->path, 1);
+ if (opts->new_branch_force || (head_ref &&
+ (!(flag & REF_ISSYMREF) || strcmp(head_ref, check_branch_path))))
+ die_if_checked_out(check_branch_path, 1);
I don't think it is worth a re-roll but the reformatting here is
unfortunate. If you add the new condition at the end it is clearer what
is being changed.
if ((head_ref &&
(!(flag & REF_IS_YMREF) || strcmp(head_ref, check_branch_path))) ||
opts->new_branch_force)
preserves the original code structure so one can see we've added a new
condition and done s/new_branch_info->path/check_branch_path/
free(head_ref);
}
@@ -1627,7 +1628,9 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
const char * const usagestr[],
struct branch_info *new_branch_info)
{
+ int ret;
int parseopt_flags = 0;
+ char *check_branch_path = NULL;
opts->overwrite_ignore = 1;
opts->prefix = prefix;
@@ -1717,6 +1720,13 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
opts->new_branch = argv0 + 1;
}
+ if (opts->new_branch && !opts->ignore_other_worktrees) {
+ struct strbuf buf = STRBUF_INIT;
+
+ strbuf_branchname(&buf, opts->new_branch, INTERPRET_BRANCH_LOCAL);
+ strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
+ check_branch_path = strbuf_detach(&buf, NULL);
+ }
This block will run whenever -b/-B is given which is good
/*
* Extract branch name from command line arguments, so
* all that is left is pathspecs.
@@ -1741,6 +1751,9 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
new_branch_info, opts, &rev);
argv += n;
argc -= n;
+
+ if (!opts->ignore_other_worktrees && !check_branch_path && new_branch_info->path)
+ check_branch_path = xstrdup(new_branch_info->path);
I'm a bit confused what this is doing.
} else if (!opts->accept_ref && opts->from_treeish) {
struct object_id rev;
@@ -1817,9 +1830,12 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
}
if (opts->patch_mode || opts->pathspec.nr)
- return checkout_paths(opts, new_branch_info);
+ ret = checkout_paths(opts, new_branch_info);
else
- return checkout_branch(opts, new_branch_info);
+ ret = checkout_branch(opts, new_branch_info, check_branch_path);
+
+ free(check_branch_path);
+ return ret;
This is clearer now - thanks
}
int cmd_checkout(int argc, const char **argv, const char *prefix)
diff --git a/t/t2400-worktree-add.sh b/t/t2400-worktree-add.sh
index d587e0b20d..7ab7e87440 100755
--- a/t/t2400-worktree-add.sh
+++ b/t/t2400-worktree-add.sh
@@ -118,14 +118,17 @@ test_expect_success '"add" worktree creating new branch' '
)
'
-test_expect_success 'die the same branch is already checked out' '
+test_expect_success 'die if the same branch is already checked out' '
(
cd here &&
- test_must_fail git checkout newmain
+ test_must_fail git checkout newmain &&
+ test_must_fail git checkout -B newmain &&
+ test_must_fail git switch newmain &&
+ test_must_fail git switch -C newmain
)
'
-test_expect_success SYMLINKS 'die the same branch is already checked out (symlink)' '
+test_expect_success SYMLINKS 'die if the same branch is already checked out (symlink)' '
head=$(git -C there rev-parse --git-path HEAD) &&
ref=$(git -C there symbolic-ref HEAD) &&
rm "$head" &&
@@ -133,17 +136,34 @@ test_expect_success SYMLINKS 'die the same branch is already checked out (symlin
test_must_fail git -C here checkout newmain
'
-test_expect_success 'not die the same branch is already checked out' '
+test_expect_success 'allow creating multiple worktrees for same branch with force' '
+ git worktree add --force anothernewmain newmain
+'
+
+test_expect_success 'allow checkout/reset from the conflicted branch' '
I'm not sure what "the conflicted branch" means (it reminds we of merge
conflicts). Is this just testing that "checkout -b/B <branch>
<start-point>" works?
(
cd here &&
- git worktree add --force anothernewmain newmain
+ git checkout -b conflictedmain newmain &&
+ git checkout -B conflictedmain newmain &&
+ git switch -C conflictedmain newmain
+ )
+'
+
+test_expect_success 'and not die on re-checking out current branch even if conflicted' '
I think 'allow re-checking out ...' would be clearer, again I'm not sure
what's conflicted here.
+ (
+ cd there &&
+ git checkout newmain &&
+ git switch newmain
)
'
-test_expect_success 'not die on re-checking out current branch' '
+test_expect_failure 'unless using force without --ignore-other-worktrees' '
This test passes for me - what's the reason for changing from
test_expect_success to test_expect_failure?
Thanks for working on this
Phillip
(
cd there &&
- git checkout newmain
+ test_must_fail git checkout -B newmain &&
+ test_must_fail git switch -C newmain &&
+ git checkout --ignore-other-worktrees -B newmain &&
+ git switch --ignore-other-worktrees -C newmain
)
'
